<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-type" content="text/html; charset=iso-8859-1">
<title>Using JSTL - The Java EE 5 Tutorial</title>
<meta name="robots" content="index,follow">
<meta name="robots" content="index,follow">
<meta name="date" content="2008-10-01">
<link rel="stylesheet" type="text/css" href="css/default.css">
<link rel="stylesheet" type="text/css" href="css/ipg.css">
<link rel="stylesheet" type="text/css" href="css/j5eetutorial.css">
</head>

<body>

<table border="0" cellpadding="5" cellspacing="0" width="100%">
<tbody>
   <tr valign="top">
      <td><p class="toc level1"><a href="docinfo.html">Document Information</a></p>
<p class="toc level1 tocsp"><a href="gexaf.html">Preface</a></p>
<p class="toc level1 tocsp"><a href="gfirp.html">Part&nbsp;I&nbsp;Introduction</a></p>
<p class="toc level2"><a href="bnaaw.html">1.&nbsp;&nbsp;Overview</a></p>
<p class="toc level2"><a href="gfiud.html">2.&nbsp;&nbsp;Using the Tutorial Examples</a></p>
<p class="toc level1 tocsp"><a href="bnadp.html">Part&nbsp;II&nbsp;The Web Tier</a></p>
<p class="toc level2"><a href="bnadr.html">3.&nbsp;&nbsp;Getting Started with Web Applications</a></p>
<p class="toc level2"><a href="bnafd.html">4.&nbsp;&nbsp;Java Servlet Technology</a></p>
<p class="toc level2"><a href="bnagx.html">5.&nbsp;&nbsp;JavaServer Pages Technology</a></p>
<p class="toc level2"><a href="bnajo.html">6.&nbsp;&nbsp;JavaServer Pages Documents</a></p>
<p class="toc level2"><a href="bnakc.html">7.&nbsp;&nbsp;JavaServer Pages Standard Tag Library</a></p>
<p class="toc level3"><a href="bnakd.html">The Example JSP Pages</a></p>
<div class="onpage">
<p class="toc level3"><a href="">Using JSTL</a></p>
<p class="toc level4"><a href="#bnakg">Tag Collaboration</a></p>
</div>
<p class="toc level3 tocsp"><a href="bnakh.html">Core Tag Library</a></p>
<p class="toc level4"><a href="bnakh.html#bnakj">Variable Support Tags</a></p>
<p class="toc level4"><a href="bnakh.html#bnakk">Flow Control Tags</a></p>
<p class="toc level5"><a href="bnakh.html#bnakl">Conditional Tags</a></p>
<p class="toc level5"><a href="bnakh.html#bnakm">Iterator Tags</a></p>
<p class="toc level4 tocsp"><a href="bnakh.html#bnakn">URL Tags</a></p>
<p class="toc level4"><a href="bnakh.html#bnako">Miscellaneous Tags</a></p>
<p class="toc level3 tocsp"><a href="bnakq.html">XML Tag Library</a></p>
<p class="toc level4"><a href="bnakq.html#bnakt">Core Tags</a></p>
<p class="toc level4"><a href="bnakq.html#bnaku">Flow Control Tags</a></p>
<p class="toc level4"><a href="bnakq.html#bnakv">Transformation Tags</a></p>
<p class="toc level3 tocsp"><a href="bnakw.html">Internationalization Tag Library</a></p>
<p class="toc level4"><a href="bnakw.html#bnaky">Setting the Locale</a></p>
<p class="toc level4"><a href="bnakw.html#bnakz">Messaging Tags</a></p>
<p class="toc level5"><a href="bnakw.html#bnala">The <tt>setBundle</tt> and <tt>bundle</tt> Tags</a></p>
<p class="toc level5"><a href="bnakw.html#bnalb">The <tt>message</tt> Tag</a></p>
<p class="toc level4 tocsp"><a href="bnakw.html#bnalc">Formatting Tags</a></p>
<p class="toc level3 tocsp"><a href="bnald.html">SQL Tag Library</a></p>
<p class="toc level4"><a href="bnald.html#bnalf"><tt>query</tt> Tag Result Interface</a></p>
<p class="toc level3 tocsp"><a href="bnalg.html">JSTL Functions</a></p>
<p class="toc level3"><a href="bnali.html">Further Information about JSTL</a></p>
<p class="toc level2 tocsp"><a href="bnalj.html">8.&nbsp;&nbsp;Custom Tags in JSP Pages</a></p>
<p class="toc level2"><a href="bnaon.html">9.&nbsp;&nbsp;Scripting in JSP Pages</a></p>
<p class="toc level2"><a href="bnaph.html">10.&nbsp;&nbsp;JavaServer Faces Technology</a></p>
<p class="toc level2"><a href="bnaqz.html">11.&nbsp;&nbsp;Using JavaServer Faces Technology in JSP Pages</a></p>
<p class="toc level2"><a href="bnatx.html">12.&nbsp;&nbsp;Developing with JavaServer Faces Technology</a></p>
<p class="toc level2"><a href="bnavg.html">13.&nbsp;&nbsp;Creating Custom UI Components</a></p>
<p class="toc level2"><a href="bnawo.html">14.&nbsp;&nbsp;Configuring JavaServer Faces Applications</a></p>
<p class="toc level2"><a href="bnaxu.html">15.&nbsp;&nbsp;Internationalizing and Localizing Web Applications</a></p>
<p class="toc level1 tocsp"><a href="bnayk.html">Part&nbsp;III&nbsp;Web Services</a></p>
<p class="toc level2"><a href="bnayl.html">16.&nbsp;&nbsp;Building Web Services with JAX-WS</a></p>
<p class="toc level2"><a href="bnazf.html">17.&nbsp;&nbsp;Binding between XML Schema and Java Classes</a></p>
<p class="toc level2"><a href="bnbdv.html">18.&nbsp;&nbsp;Streaming API for XML</a></p>
<p class="toc level2"><a href="bnbhf.html">19.&nbsp;&nbsp;SOAP with Attachments API for Java</a></p>
<p class="toc level1 tocsp"><a href="bnblr.html">Part&nbsp;IV&nbsp;Enterprise Beans</a></p>
<p class="toc level2"><a href="bnbls.html">20.&nbsp;&nbsp;Enterprise Beans</a></p>
<p class="toc level2"><a href="bnbnb.html">21.&nbsp;&nbsp;Getting Started with Enterprise Beans</a></p>
<p class="toc level2"><a href="bnboc.html">22.&nbsp;&nbsp;Session Bean Examples</a></p>
<p class="toc level2"><a href="bnbpk.html">23.&nbsp;&nbsp;A Message-Driven Bean Example</a></p>
<p class="toc level1 tocsp"><a href="bnbpy.html">Part&nbsp;V&nbsp;Persistence</a></p>
<p class="toc level2"><a href="bnbpz.html">24.&nbsp;&nbsp;Introduction to the Java Persistence API</a></p>
<p class="toc level2"><a href="bnbrl.html">25.&nbsp;&nbsp;Persistence in the Web Tier</a></p>
<p class="toc level2"><a href="bnbrs.html">26.&nbsp;&nbsp;Persistence in the EJB Tier</a></p>
<p class="toc level2"><a href="bnbtg.html">27.&nbsp;&nbsp;The Java Persistence Query Language</a></p>
<p class="toc level1 tocsp"><a href="bnbwi.html">Part&nbsp;VI&nbsp;Services</a></p>
<p class="toc level2"><a href="bnbwj.html">28.&nbsp;&nbsp;Introduction to Security in the Java EE Platform</a></p>
<p class="toc level2"><a href="bnbyk.html">29.&nbsp;&nbsp;Securing Java EE Applications</a></p>
<p class="toc level2"><a href="bncas.html">30.&nbsp;&nbsp;Securing Web Applications</a></p>
<p class="toc level2"><a href="bncdq.html">31.&nbsp;&nbsp;The Java Message Service API</a></p>
<p class="toc level2"><a href="bncgv.html">32.&nbsp;&nbsp;Java EE Examples Using the JMS API</a></p>
<p class="toc level2"><a href="bncih.html">33.&nbsp;&nbsp;Transactions</a></p>
<p class="toc level2"><a href="bncjh.html">34.&nbsp;&nbsp;Resource Connections</a></p>
<p class="toc level2"><a href="bncjx.html">35.&nbsp;&nbsp;Connector Architecture</a></p>
<p class="toc level1 tocsp"><a href="bnckn.html">Part&nbsp;VII&nbsp;Case Studies</a></p>
<p class="toc level2"><a href="bncko.html">36.&nbsp;&nbsp;The Coffee Break Application</a></p>
<p class="toc level2"><a href="bnclz.html">37.&nbsp;&nbsp;The Duke's Bank Application</a></p>
<p class="toc level1 tocsp"><a href="gexbq.html">Part&nbsp;VIII&nbsp;Appendixes</a></p>
<p class="toc level2"><a href="bncno.html">A.&nbsp;&nbsp;Java Encoding Schemes</a></p>
<p class="toc level2"><a href="bncnq.html">B.&nbsp;&nbsp;Preparation for Java EE Certification Exams</a></p>
<p class="toc level2"><a href="bncnt.html">C.&nbsp;&nbsp;About the Authors</a></p>
<p class="toc level1 tocsp"><a href="idx-1.html">Index</a></p>
</td>
      <td width="10px">&nbsp;</td>
      <td width="705px">
         <div class="header">
             <div class="header-links-top">
                 <a href="http://java.sun.com">java.sun.com</a> |
                 <a href="http://docs.sun.com/">docs.sun.com</a><br>
             </div> 
             <img src="graphics/tutorialBanner.gif" width="704" height="120" alt="The Java&trade; EE 5 Tutorial"/>
             <div class="header-links">
	         <a href="index.html">Home</a> |
                 <a href="http://java.sun.com/javaee/5/docs/tutorial/information/download.html">Download</a> |
                 <a href="http://java.sun.com/javaee/5/docs/tutorial/doc/JavaEETutorial.pdf">PDF</a> |
                 <a href="http://java.sun.com/javaee/5/docs/api/index.html">API</a> |
                 <a href="http://java.sun.com/javaee/5/docs/tutorial/information/faq.html">FAQ</a> |
                 <a href="http://java.sun.com/javaee/5/docs/tutorial/information/search.html">Search</a> |
                 <a href="http://java.sun.com/javaee/5/docs/tutorial/information/sendusmail.html">Feedback</a> |
                 <a href="http://java.sun.com/javaee/5/docs/tutorial/information/history.html">History</a>
             </div>
             <div class="navigation">
                 <a href="bnakd.html"><img style="padding-right: 3px" src="graphics/leftButton.gif" border="0"></a>
                 <a href="sjsaseej2eet.html"><img style="padding-right: 3px" src="graphics/upButton.gif" border="0"></a>
                 <a href="bnakh.html"><img style="padding-left: 3px" src="graphics/rightButton.gif" border="0"></a>
             </div>
         </div>

	 <div class="maincontent">      	 
             

<a name="bnake"></a><h3>Using JSTL</h3>
<p>JSTL includes a wide variety of tags that fit into discrete functional areas.
To reflect this, as well as to give each area its own
namespace, JSTL is exposed as multiple tag libraries. The URIs for the libraries
are as follows:</p>
<ul><li><p><b>Core</b>: <a href="http://java.sun.com/jsp/jstl/core">http://java.sun.com/jsp/jstl/core</a></p></li>
<li><p><b>XML</b>: <a href="http://java.sun.com/jsp/jstl/xml">http://java.sun.com/jsp/jstl/xml</a></p></li>
<li><p><b>Internationalization</b>: <a href="http://java.sun.com/jsp/jstl/fmt">http://java.sun.com/jsp/jstl/fmt</a></p></li>
<li><p><b>SQL</b>: <a href="http://java.sun.com/jsp/jstl/sql">http://java.sun.com/jsp/jstl/sql</a></p></li>
<li><p><b>Functions</b>: <a href="http://java.sun.com/jsp/jstl/functions">http://java.sun.com/jsp/jstl/functions</a></p></li></ul>
<p><a href="#bnakf">Table&nbsp;7-1</a> summarizes these functional areas along with the prefixes used in this tutorial.</p><a name="bnakf"></a><h6>Table&nbsp;7-1 JSTL Tags</h6><table><col width="28%"><col width="50%"><col width="20%"><tr><th align="left" valign="top" scope="column"><p>Area</p></th>
<th align="left" valign="top" scope="column"><p>Subfunction</p></th>
<th align="left" valign="top" scope="column"><p>Prefix</p></th>
</tr>
<tr><td rowspan="4" align="left" valign="top" scope="row"><p><b>Core</b></p></td>
<td align="left" valign="top" scope="row"><p>Variable
support</p></td>
<td rowspan="4" align="left" valign="top" scope="row"><p><tt>c</tt></p></td>
</tr>
<tr><td align="left" valign="top" scope="row"><p>Flow control</p></td>
</tr>
<tr><td align="left" valign="top" scope="row"><p>URL management</p></td>
</tr>
<tr><td align="left" valign="top" scope="row"><p>Miscellaneous</p></td>
</tr>
<tr><td rowspan="3" align="left" valign="top" scope="row"><p><b>XML</b></p></td>
<td align="left" valign="top" scope="row"><p>Core</p></td>
<td rowspan="3" align="left" valign="top" scope="row"><p><tt>x</tt></p></td>
</tr>
<tr><td align="left" valign="top" scope="row"><p>Flow control</p></td>
</tr>
<tr><td align="left" valign="top" scope="row"><p>Transformation</p></td>
</tr>
<tr><td rowspan="3" align="left" valign="top" scope="row"><p><b>I18N</b></p></td>
<td align="left" valign="top" scope="row"><p>Locale</p></td>
<td rowspan="3" align="left" valign="top" scope="row"><p><tt>fmt</tt></p></td>
</tr>
<tr><td align="left" valign="top" scope="row"><p>Message formatting</p></td>
</tr>
<tr><td align="left" valign="top" scope="row"><p>Number and date formatting</p></td>
</tr>
<tr><td align="left" valign="top" scope="row"><p><b>Database</b></p></td>
<td align="left" valign="top" scope="row"><p>SQL</p></td>
<td align="left" valign="top" scope="row"><p><tt>sql</tt></p></td>
</tr>
<tr><td rowspan="2" align="left" valign="top" scope="row"><p><b>Functions</b></p></td>
<td align="left" valign="top" scope="row"><p>Collection length</p></td>
<td rowspan="2" align="left" valign="top" scope="row"><p><tt>fn</tt></p></td>
</tr>
<tr><td align="left" valign="top" scope="row"><p>String manipulation</p></td>
</tr>
</table><p>Thus, the tutorial references the JSTL core tags in JSP pages by
using the following <tt>taglib</tt> directive:</p><pre>&lt;%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %></pre><p>In addition to declaring the tag libraries, tutorial examples access the JSTL API
and implementation. In the Application Server, the JSTL TLDs and libraries are distributed
in the archive <tt></tt><i>as-install</i><tt>/lib/appserv-jstl.jar</tt>. This library is automatically loaded into the classpath
of all web applications running on the Application Server, so you don&rsquo;t need to
add it to your web application.</p>

<a name="bnakg"></a><h4>Tag Collaboration</h4>
<p>Tags usually collaborate with their environment in implicit and explicit ways. <b>Implicit</b> collaboration
is done by means of a well-defined interface that allows nested tags to
work seamlessly with the ancestor tag that exposes that interface. The JSTL conditional
tags employ this mode of collaboration.</p><p><b>Explicit</b> collaboration happens when a tag exposes information to its environment. JSTL tags
expose information as JSP EL variables; the convention followed by JSTL is to
use the name <tt>var</tt> for any tag attribute that exports information about the
tag. For example, the <tt>forEach</tt> tag exposes the current item of the
shopping cart it is iterating over in the following way:</p><pre>&lt;c:forEach var="item" items="${sessionScope.cart.items}">
    ...
&lt;/c:forEach></pre><p>In situations where a tag exposes more than one piece of information, the
name <tt>var</tt> is used for the primary piece of information being exported, and
an appropriate name is selected for any other secondary piece of information exposed.
For example, iteration status information is exported by the <tt>forEach</tt> tag through the
attribute <tt>status</tt>.</p><p>When you want to use an EL variable exposed by a JSTL
tag in an expression in the page&rsquo;s scripting language (see <a href="bnaon.html">Chapter&nbsp;9, Scripting in JSP Pages</a>), you use
the standard JSP element <tt>jsp:useBean</tt> to declare a scripting variable.</p><p>For example, <tt></tt><i>tut-install</i><tt>/javaeetutorial5/examples/web/bookstore4/web/books/bookshowcart.jsp</tt> removes a book from a shopping cart using a
scriptlet. The ID of the book to be removed is passed as a
request parameter. The value of the request parameter is first exposed as an
EL variable (to be used later by the JSTL <tt>sql:query</tt> tag) and then
is declared as a scripting variable and passed to the <tt>cart.remove</tt> method:</p><pre>&lt;c:set var="bookId" value="${param.Remove}"/>
&lt;jsp:useBean id="bookId" type="java.lang.String" />
&lt;% cart.remove(bookId); %>
&lt;sql:query var="books"
     dataSource="${applicationScope.bookDS}">
    select * from PUBLIC.books where id = ?
    &lt;sql:param value="${bookId}" />
&lt;/sql:query></pre>
         </div>
         <div class="navigation">
             <a href="bnakd.html"><img style="padding-right: 3px" src="graphics/leftButton.gif" border="0"></a>
             <a href="sjsaseej2eet.html"><img style="padding-right: 3px" src="graphics/upButton.gif" border="0"></a>
             <a href="bnakh.html"><img style="padding-left: 3px" src="graphics/rightButton.gif" border="0"></a>
         </div>

         <div class="copyright">
      	    <p>The material in The Java&trade; EE 5 Tutorial is <a href='docinfo.html'>copyright</a>-protected and may not be published in other works without express written permission from Sun Microsystems.</p>
      	 </div>

      </td>
   </tr>
</tbody>
</table>
</body>
</html>

